From 1fb202fa89e7b0352521daf224a72fecb9fff342 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=BA=90=E6=96=87=E9=9B=A8?=
 <41315874+fumiama@users.noreply.github.com>
Date: Tue, 14 Oct 2025 17:03:32 +0800
Subject: [PATCH] feat: add test `USM explicit data movement`

---
 tests/fig-3-4_usm-explicit-data-movement.cpp | 46 ++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 tests/fig-3-4_usm-explicit-data-movement.cpp

diff --git a/tests/fig-3-4_usm-explicit-data-movement.cpp b/tests/fig-3-4_usm-explicit-data-movement.cpp
new file mode 100644
index 0000000..91ba25d
--- /dev/null
+++ b/tests/fig-3-4_usm-explicit-data-movement.cpp
@@ -0,0 +1,46 @@
+// Figure 3-4. USM explicit data movement
+// from book - Data Parallel C++
+// https://link.springer.com/book/10.1007/978-1-4842-5574-2
+
+#include <array>
+#include <sycl/sycl.hpp>
+
+constexpr int N = 42;
+
+int main() {
+  sycl::queue Q;
+
+  std::array<int, N> host_array;
+  int *device_array = sycl::malloc_device<int>(N, Q);
+
+  for (int i = 0; i < N; i++) {
+    host_array[i] = N;
+  }
+
+  // We will learn how to simplify this example later
+  Q.submit([&](sycl::handler &h) {
+     // copy hostArray to deviceArray
+     h.memcpy(device_array, &host_array[0], N * sizeof(int));
+   }).wait();
+
+  Q.submit([&](sycl::handler &h) {
+     h.parallel_for(N, [=](sycl::id<1> i) { device_array[i]++; });
+   }).wait();
+
+  Q.submit([&](sycl::handler &h) {
+     // copy deviceArray back to hostArray
+     h.memcpy(&host_array[0], device_array, N * sizeof(int));
+   }).wait();
+
+  sycl::free(device_array, Q);
+
+  for (int i = 0; i < host_array.size(); i++) {
+    if (host_array[i] != N + 1) {
+      std::cerr << "Expect " << N + 1 << " at idx " << i << " but got " << host_array[i]
+                << std::endl;
+      return -1;
+    }
+  }
+
+  return 0;
+}
\ No newline at end of file